SSD manufacturers are under constant pressure to reduce prices and increase capacity, but the pace of Moore's Law is never enough to satisfy consumers. As the SSD industry has matured, manufacturers have turned to other strategies for driving down costs, making tradeoffs to better suit what customers want. Early on, we saw a shift from single bit-per-cell SLC NAND to two bit-per-cell MLC, doubling capacity for the same size of chip (and therefore, cutting cost per GB in half). Currently, the industry is transitioning to 3D NAND techniques that allow for more storage capacity on a chip of a given size without requiring circuit elements and memory cells to shrink. Portions of the market are also shifting to use three bit-per-cell TLC NAND to get another capacity boost.

None of these advancements in storage density come for free. 3D NAND requires major changes to the manufacturing process, which is why only one of the four NAND manufacturers is currently shipping products with 3D NAND. Likewise, cramming more bits into the same memory cell has reprecussions. The more closely spaced voltage levels in the flash cells requires more careful control and more complicated error correction. It makes reading and especially writing slower, drives up power consumption and decreases durability. Everyone in the industry has struggled to create TLC-based SSDs that can compete on anything other than cost. Samsung has made the most use of TLC, aided by their lead in 3D NAND, but their TLC drives have had issues that have proven tough to stamp out. Despite the difficulty, most manufacturers now feel that TLC has a place in the market and that the downsides can be mitigated enough to suit consumers.

This brings us to Crucial's latest drive, the BX200. As the successor to the very successful BX100, it is a value-oriented 2.5" SATA drive. The BX200 moves to the newer Silicon Motion SM2256 controller and is Crucial and Micron's first TLC drive, using Micron's 128Gb 16nm TLC NAND. Micron's 16nm TLC was announced in June as intended for consumer applications. With a shift to 3D NAND planned for 2016, their 16nm TLC is something of a stopgap solution to further cut costs while temporarily stuck at the end of the road for planar NAND.

Silicon Motion's SM2246EN controller has been a popular choice for low-cost client drives, and when paired with MLC NAND it offers decent performance and very low power consumption. While it technically supports TLC NAND, only the successor SM2256 controller supports the more advanced LDPC error correction that is widely viewed as necessary to get sufficient reliability from a TLC drive. There are now several TLC drives on the market using the SM2256, competing primarily against each other and earlier SM2246EN drives with MLC, and MLC and TLC drives using Phison S10 controllers. Further up the price and performance scale are mid-range MLC drives and Samsung's TLC-based 850 Evo.

Crucial 480/500/512GB SSD Comparison

Drive

BX100

BX200

MX200

Controller

Silicon Motion SM2246EN

Silicon Motion SM2256

Marvell 88SS9189

NAND

Micron 16nm 128Gbit MLC

Micron 16nm 128Gbit TLC NAND

Micron 16nm 128Gbit MLC

Sequential Read

535 MB/s

540 MB/s

555 MB/s

Sequential Write

450 MB/s

490 MB/s

500 MB/s

4kB Random Read

90k IOPS

66k IOPS

100k IOPS

4kB Random Write

70k IOPS

78k IOPS

87k IOPS

Endurance

72 TB

72 TB

160 TB

Warranty

3 years

The BX200 specifications show only moderate performance increases over the BX100, except for the random read speed which is significantly decreased. The higher program and erase times of TLC NAND are probably the most difficult downside to mitigate, as SSDs have always been trying to compensate for their much higher latency than DRAM. Throughput can be increased by using multiple flash chips in parallel, but random read performance ultimately is limited by how long it takes the drive to fetch any data from the flash chips, so some decrease was probably unavoidable.

With the BX200 Crucial is retiring the 128GB capacity class. As flash memory gets cheaper, the fixed costs of the controller and other components come to dominate the budget and smaller capacity drives end up costing more per GB than mid-range capacities. Additionally, the smallest capacities have the least ability to provide parallelism, which can hobble their performance.

For most of the charts in this review, I've highlighted in blue the other TLC drives we've tested.

86 Comments

The 2013 benchmarks include a "Intel X25-M G2 160GB" (or the 80GB) which is what I'm going to assume is an Intel G2.

You can compare 1 to 1 with any SSD for example with a 250GB 850 Evo you see big gains just about everywhere, so you will definitely gain performance but will that actually be noticeable to you i have no idea because it depends on what you will use it for. For sure it won't be AS big a gap as going from a HDD to an SSD was but you may notice some small gains. It's hilarious because in the overall listing of all the ssd's there is a "Velociraptor 10,000 rpm" HDD to compare to the SSD's which is awesome. Keep in mind also that you get a new (probably better) warranty and a larger guaranteed durability.Reply

Maybe you got lucky, but I bought one after reading some good reviews (before the nand change fiasco hit the news) and after a while I noticed something was wrong because of the painfully slow performance. It was giving me reads close to 100MB/s and writes on the 20MB/s range, and that's sequential performance. I usually do not notice any difference in tel world performance between different SSD models, but with the V300 was very notorious. Even the HDD I had in use at the time felt faster (Spinpoint F1 1TB). So no, the V300 is not faster than any HDD.Reply